Hi there
My son is 13 and I had him during my first marriage. I have since had 3 more children with my 'new' husband. Well he's actually not new at all but you get the picture 
At home, my son has boundaries, he's not allowed to wander the streets etc, I have to know where he is. He also has a few additional needs which makes this even more important.
However the weekends he goes to his dad's are a different story. He is allowed to wander round town all day, even after dark 
This is not how I ever want any of my children brought up. On discussing it with my ex husband, he thinks I'm soft and am ridiculous trying to set these boundaries and that life in the town he lives in is not sheltered like the village I grew up in ! I argued this point because it wouldn't matter where we live, my children will never be allowed to roam the streets and hang out at bus stops! This isn't about area, it's about good and safe parenting! Anything could happen... I told my son that even when he's at his dads, he needs to let me know where he is etc.
However, the last month has been a challenge to say the least. My son has started to literally do as he wants - for example, school was opening late because of the snow, but the building was open. My son was already on the way to school so I told him just to go in and work in the library. I found out later that he'd actually just gone and hung around on the streets again. This really upset me as we had specifically stated he was to go to school so we knew where he was (I was at work)
I feel so upset - how can I fight this lax parenting which seems so great to my son at the moment? My ex seems to see this as a way in and to gain brownie points from my son, so I look the mean one. It's happening at a pivotal point in my son's life when he should be learning acceptable boundaries and behaviours.
After driving to collect my boy from town at 8pm on Friday night because my ex said 'he'll be fine', my ex actually laughed at me in front of my son and called me a kill joy 
I'm going to lose my son to this, I can feel it